Explanation

Long-Term Time-Series Data

References of Long-Term Time-Series Data of IOPI (before 1995 base)

New 1990 base index

Note: The new 1990 base index is compiled by a new method that is applied to the 1995 base index henceforth. With the introduction of the new method, an additional survey for the IOPI compilation was abolished and the data transferred from the CGPI survey is used to compile the index.